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With a large number of scientific and technological development and natural resources developed using a large number of inorganic and organic compounds followed them into the human environment, causing extensive pollution of water, air, soil and food, causing food safety issues, including heavy metals pollution become in recent years the UNDP / FAO / WHO Global food contamination monitoring program in important projects, but also China's current focus on monitoring the project. Tomato sauce as an of Xinjiang important export products. Due to the unique geographical environment, the quality of tomato in Xinjiang is also internationally recognized, its quality is better than the main producing countries such as the United States, Italy, is one of the few areas suitable for planting tomatoes in the world, is also one of the world's three major tomato production centers. Products are welcomed by the trading nations of the European Union, Japan and North America. Tomato sauce contains a relatively large number of heavy metals such as arsenic, mercury, lead, tin, and sometimes serious side effects of heavy metals on the human body has a certain residues in food excess heavy metals, may cause serious hazards. The establishment of means of detection of heavy metals in tomato sauce, is an important measure to ensure food safety. At the same time, we can improve the competitiveness of the tomato sauce in the international market. Experiment arsenic, mercury, lead, tin four main elements is selected as the research object, has important practical significance and value. The purpose of this study: Atomic Fluorescence Spectrometry food arsenic, mercury, lead, and tin, and the simultaneous determination of arsenic and mercury were established to provide a theoretical basis for the establishment of ketchup atomic fluorescence spectrometry testing standards. Methods: nitric acid - hydrogen peroxide digestion system by microwave digestion method for sample pre-treatment method. The use of intermittent flow injection - hydride generation - atomic fluorescence spectrometer (AFS-9800) were optimized single-element detection conditions, and on this basis to explore the joint measurement of the two-element method, give full play to the performance of the instrument, to further improve work efficiency, reduce the cost of analysis. Mainly include the following contents: Application AFS-9800 atomic fluorescence spectrometer, microwave digestion pre-treatment system, sample pre-treatment conditions (HNO3-H2O2) digestion system, KBH4-NaOH Reaction System; optimum detection of the condition of perfect ; discussed in acid medium, the concentration of hydrochloric acid, carrier gas flow rate, the height of atomizer photomultiplier negative high voltage cathode lamp current for the detection of arsenic, mercury, lead and tin detection. Through the trial record large amounts of data, the establishment of associated of AFS detection of arsenic, mercury, lead, tin, and combined detection of mercury - arsenic detection method. Results: Under the optimum conditions, the arsenic 0.0μg / L ~ 10.0μg / L working curve correlation coefficient of 0.9998, the detection limit was 0.0122μg / L, the relative standard deviation was 0.9%; mercury 0.0μg/L-10.0μg/L The work curve correlation coefficient of 0.9999, and the detection limit was 0.0015μg / L, the relative standard deviation was 1.2%. The correlation coefficient of the lead 0.0gg / L ~ 10.0μg / L working curve was 0.9997, the detection limit for 0.0023μg / L, the relative standard deviation was 1.66%; tin-0.0μg / L ~~ 100.0μg / L working curve correlation coefficient of 0.9997 The detection limit is 0.0011μg / L, the relative standard deviation was 1.05%. Arsenic - mercury joint measurement conditions, arsenic 0.0μg / L ~ 10.0μg / L working curve correlation coefficient was 0.9994, the detection limit was 0.0029μg / L, the relative standard deviation was 0.38%; mercury 0.0μg / L to 1.0 μg / L curve correlation coefficient of 0.9996 the detection limit 0.0075μg / L, the relative standard deviation was 0.25%. Arsenic recovery of spiked 94.2% -102.7% the mercury spiked recoveries were 90.66% -101.49%, lead recoveries were 94.61% -100.11% tin spiked recoveries in the range of 92.01% -99.08%, arsenic and mercury simultaneous detection of arsenic and mercury spiked recoveries were 91.09% -100.43% 93.06% -101.21%. Conclusion: The above method for the determination of the National Standard Reference Materials the cabbage (GBW10014) and spinach (GBW10015) of arsenic, mercury, lead and tin, measured values ??and national standards recommended values ??consistent. Show that this method has a simple, rapid, accurate simultaneous detection of arsenic, mercury, lead, tin detection and arsenic and mercury, with satisfactory results, used in tomato sauce.
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